import WxCanvas from "./wx-canvas";
import * as echarts from "./echarts";

let ctx;

Component({
  properties: {
    canvasId: {
      type: String,
      value: "ec-canvas"
    },

    ec: {
      type: Object
    }
  },

  data: {},

  ready: function() {
    if (!this.data.ec) {
      console.warn(
        '组件需绑定 ec 变量，例：<ec-canvas id="mychart-dom-bar" ' +
          'canvas-id="mychart-bar" ec="{{ ec }}"></ec-canvas>'
      );
      return;
    }

    if (!this.data.ec.lazyLoad) {
      this.init();
    }
  },

  methods: {
    init: function(callback) {
      const version = wx.version.version.split(".").map(n => parseInt(n, 10));
      const isValid =
        version[0] > 1 ||
        (version[0] === 1 && version[1] > 9) ||
        (version[0] === 1 && version[1] === 9 && version[2] >= 91);
      if (!isValid) {
        console.error(
          "微信基础库版本过低，需大于等于 1.9.91。" +
            "参见：https://github.com/ecomfe/echarts-for-weixin" +
            "#%E5%BE%AE%E4%BF%A1%E7%89%88%E6%9C%AC%E8%A6%81%E6%B1%82"
        );
        return;
      }

      ctx = wx.createCanvasContext(this.data.canvasId, this);

      const canvas = new WxCanvas(ctx, this.data.canvasId);

      echarts.setCanvasCreator(() => {
        return canvas;
      });

      var query = wx.createSelectorQuery().in(this);
      query
        .select(".ec-canvas")
        .boundingClientRect(res => {
          if (typeof callback === "function") {
            this.chart = callback(canvas, res.width, res.height);
          } else if (
            this.data.ec &&
            typeof this.data.ec.onInit === "function"
          ) {
            this.chart = this.data.ec.onInit(canvas, res.width, res.height);
          } else {
            this.triggerEvent("init", {
              canvas: canvas,
              width: res.width,
              height: res.height
            });
          }
        })
        .exec();
    },

    canvasToTempFilePath(opt) {
      if (!opt.canvasId) {
        opt.canvasId = this.data.canvasId;
      }

      ctx.draw(true, () => {
        wx.canvasToTempFilePath(opt, this);
      });
    },

    touchStart(e) {
      if (this.chart && e.touches.length > 0) {
        var touch = e.touches[0];
        var handler = this.chart.getZr().handler;
        handler.dispatch("mousedown", {
          zrX: touch.x,
          zrY: touch.y
        });
        handler.dispatch("mousemove", {
          zrX: touch.x,
          zrY: touch.y
        });
        handler.processGesture(wrapTouch(e), "start");
      }
    },

    touchMove(e) {
      if (this.chart && e.touches.length > 0) {
        var touch = e.touches[0];
        var handler = this.chart.getZr().handler;
        handler.dispatch("mousemove", {
          zrX: touch.x,
          zrY: touch.y
        });
        handler.processGesture(wrapTouch(e), "change");
      }
    },

    touchEnd(e) {
      if (this.chart) {
        const touch = e.changedTouches ? e.changedTouches[0] : {};
        var handler = this.chart.getZr().handler;
        handler.dispatch("mouseup", {
          zrX: touch.x,
          zrY: touch.y
        });
        handler.dispatch("click", {
          zrX: touch.x,
          zrY: touch.y
        });
        handler.processGesture(wrapTouch(e), "end");
      }
    }
  }
});

function wrapTouch(event) {
  for (let i = 0; i < event.touches.length; ++i) {
    const touch = event.touches[i];
    touch.offsetX = touch.x;
    touch.offsetY = touch.y;
  }
  return event;
}
